Magnetic ball transfer



J. A. SWENTON MAGNETIC BALLTRANSFER Feb 22, 949.

3 Sheets-Sheet 1 Filed Feb. 14, 1946 um v Nam w I, H m 1 m 7 1 3 4 Swazi a2a 'w Attorneys Fe, 22, @949. J. A. SWENTON $62,235

MAGNETI C BALL TRANSFER 3 Sheis-Sheet 2 Filed Feb. 14, 1946 Feb, 22, 1949. 1A, SWENTON 2,462,235

MAGNETI 0 BALL TRANSFER Filed Feb. 14, 1946 s Sheets-Sheet 3 Patented Feb. 22, 1949 UNITED STATES PATENT-OFFICE MAGNETIC BALL TRANSFER John A. Swenton, Bristol, Conn.

Application February 14, 1946, Serial N0..647,500

9 Claims.

This invention relates to a magnetic ball transfer, for grinding machines, such as ball or centerless grinding machines, designed to feed ball bearings one at a time automatically for grinding and to automatically discharge the same when the grinding operation is completed, so that all of the balls will have a standard size according to the size for which the machine is set.

Another object of the invention is to provide a magnetic ball transfer in which the balls are automatically fed for grinding and automatically discharged, the device being electrically and magnetically controlled to cause step feeding of the balls during the grinding operation so that they are automatically ground to a standard set size accurately and quickly and discharged as the grinding operation is completed.

Another object of the invention is to provide a novel and simple actuating mechanism for advancing or transferring the balls from feeding to the grinding and discharging positions and which will eliminate the complicated and expensive mechanism heretofore employed for transferring balls during such operations.

A still further object of the invention is to provide a reciprocating magnet which is automatically shifted to intermittently raise and release the balls during the grinding operation through a series of steps between grinding wheels and automatically shifted back and forth during the transferring operation by'the automatic closing of circuits to the actuating mechanism energizing the magnets and de-energizing the same to release the balls after being picked up and transferred in the energized position of the magnet, and finally released for discharge into a pan or container, after being positioned and ground in the various grinding steps or positions of the device.

A still further object of the invention is to eliminate a major portion of the mechanism employed in connection with machines now generally in use, and which is capable of application to a 'centerless grinder for grinding ball bearings or the like in. a simple and eificient manner, as well as accurately.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a sectional elevation of a magnetic ball transfer constructed in accordance with the invention. I

Figure 2 is a vertical sectional view at right angles to Figure 1. a p 3 Figure 3 is a fragmentary sectional view showing the feeding arrangement for the balls.

Figure 4 is a fragmentary perspective view showing the ball holder for use during the grinding operation.

Figure 5 is a horizontal sectional elevation taken below the magnetic transfer, and

Figure 6 is a diagrammatic view showing the wiring arrangement for the contacts and switches.

Referring to the drawings in detail, in which like character references designate corresponding parts throughout the several views, the ball transfer device is applied to a grinding machine having a base In on. which a trough or support ii is provided having a holder [2 with a tapered upper portion having sockets IS in which concave tapered pins I 4 are mounted by means of their reduced shank portions l5. .The grinding wheels l6 and I? of different diameters, operate on opposite sides of the holder in the manner shown in Figure 2 of the drawings, and are adapted to grind the balls or ball bearings l8 shown mounted in the concaved upper end or seat of the holders or pins I 4 so as to project peripherally therefrom. Thesegrinding wheels l5 and l! are'arranged in spaced series driven by shafts l9 and 20 in any suitable manner in connection with the grinding machine. A ball transfer head 2| is provided and has its lower portion tapered and similarly formed with concave recesses or grooves 22 concentrically curved at one side and havingthe other side toward the'discharge end cut away as indicated at 23 to release the same more readily when the grinding operation is completed. A formed magnet 24 is provided by winding around the reciprocating transfer head 2| when the coil 24 is magnetized and is designed to operate in a recess 25 formed in the lower end of a holder 26 extending transversely across the machine and having spindles 21 and 28 mounted on the ends thereof to operate in bearings or bushings 29 in uprights 3i? and 3| mounted on the base ill. The electromagnetic ball transfer head or pick up plate or holder 2! is adapted to move up and down by means of vertical rods, bolts or pins 32 connected I to the plate 2! and operating through sleeves or bushings 33 pressed into apertures vertically through the holder '26 and having their upper ends connected by a horizontal cross bar 34 centrally provided with a bar 35 connected with a suitable mechanism 36 for raising and lowering the same, such as by means of a suitably actuated plunger. Springs 31 are disposed between the bar 34 and the holder 26 to normally elevate the plate 2| in the recess 25 in the holder 26 and cushion the downward movement thereof. A solenoid coil 36 is provided on the spindle or projecting end 28 and forms a solenoid at one end, designed to retract the holder 26 to the left. while movement in the opposite direction may be caused by a spring 39 connected to the end 21 of the holder 26 and to a bracket 40 mounted on the upright 30 tending to normally hold the reciprocating member 26 to the right in Figure 1 of the drawings.

A solenoid 4| is mounted on an upright or bearing 42 outwardly of the upright 3| and is connected at its core or armature 43 to a plunger 44 having a reduced lower portion and having an inclined passage 45 therethrough. A feed tube 46 is disposed in an opening 41 through the upright 42 in an inclined position, to feed the balls |8 down the same and normally checked by the plunger 44 until the magnet or solenoid 4| is energizedto raise the plunger 44 and align the inclined passage 45 with the opening 41 to permit the balls to enter the latter one at a time and upon being lowered, to discharge through an inclined opening 48 leading into a discharge tube 49 for depositing the balls onto a cup 50 at the left hand end of the holder l2 and to enter one of the recesses 22 when the transfer plate 2| is magnetized and lowered so as to bodily raise the balls in a manner shown in Figure 1 and then release and deposit the same into pins or holders |4 upon the plate 2| and coil 24 being demagnetized with the transfer plate 2| lowered with holder 26, thus moving the balls step by step to the right for action upon the same by the series of grinding wheels |6 and I1, until they enter the last recess 22 for discharge into a cup 5| and'discharge tube 52 to be deposited into a pan as ground. A spring 53connects the lower reduced end of plunger 44 slidable in guide sleeve 54, to the bottom of the upright 3|, and the plunger 44 is limited in its downward movement by engagement of the downwardly facing shoulder formed by the reduced lower end of the plunger 44 with a corresponding upwardly facing shoulder at the lower portion of the upright 42 at its enlarged portion, while permitting upward movement of the plunger 44.

It will be noted from Figure 2 that each end of the holder or plate 2| is provided with two of the guide rods or spindles 21 and-28 movable through the openings in the upright frame members 36 and 3|, to maintain the device horizontally positioned and guide the same in its reciprocating movements. A lever 55 is pivoted at 56 to the holder at the plate 2| toward its left hand end and has a pair of contacts or arms 51 and 58 at its upper end spaced apart horizontally, co-acting with contacts 59 and 60 suitably supported above the bar 34 connected by the bolts or pins 32 to the plate 2| through the holder 26. The contacts 59 and 60 are connected to the line wires for a suitable source of energy indicated at 6| and 62 which are in turn connected to the solenoid coil 38 and solenoid 4| with an interposed control switch 63. A control switch 64 is also provided in the line 62 and connected to a bar lifting device or contact 65 adapted to engage a contact 66 mounted on and movable with the holder 26 so that when the latter is shifted to the right it will engage with contact 65. and close the circuit to the bar lifting device. Contacts 61 and 68 are provided on the holder 26 and the upright 30 respectively spaced apart when the holder 26 is moved to the left and adapted to engage when the holder 26 is moved to the right, to close the circuit to the solenoid coil 4|. After each intermittent grinding operation, the magnet 2| is energized and raised to bodily raise the balls in the manner shown in Figure 1 of the drawings and move the same to the right to the dotted line position, after which the magnet 2| is de-energized at coil 24 to release the balls into the holders or cups formed by the pins l4 for another grinding operation, until the various steps shown as nine in number are completed and the balls are accurately ground and discharged into the cup 5| upon de-energization of the magnet 2| at the coil 24, for discharge into the outlet tube 52.

Thus, in the operation of the device, as the balls enter the feeding receptacle or cup 50 through the pipe 49, one at a time or singly, the ball transfer or plate 2| due to energization of the coil 24 formed thereon, is raised and picks up the ball when the lever 55 which is attached to the plate 2| and moves therewith, engages the copper contact 59. Due to the coil 24 receiving the current, the plate 2| is magnetized to form an electromagnet, which attracts and raises the ball to hold it in the groove or recess 22 at that point over the cup 50. The magnet is guided in its upward movement by the bolts or rods 32 connected by the cross bar 34 as they slide up and down in the bushings 33 in the holder 26. When this takes place, the lever arm 58 is connected with the contact 66 to cause energization of the solenoid or magnet 38 after attracting the armature produced by the guide rod or spindle 28 and holding the ball transfer to the left. When the magnet moves upwardly in the holder to raise the balltherewith so as to clear the holders or pins I4 and the ribs in the grinding wheels, the arm 58 disengages from the contact 66, thus de-energizing the magnet 38's0 that the spring 39 will move the holder to the right. This moves the ball transfer plate 2| to the right so as to position the balls over the next series of holders or pins I4, and so that the balls will be in line with the grooves of the wheels. A lever 65 is set to engage the contact 66 and trip the grinding switch which starts the mechanism when coming in contact with the bar 34 to which the ball transfer plate 2| is attached, thus lowering the same into the grinding position and releasing the balls into the holders or pins l4 upon de-energization of the coil 24 and electro-magnet formed by the plate 2|. At this position, the lever 55 disengages the contact 59 de-magnetizing the coil 24 and releasing the balls to be dropped into the receptacle or cup 5|. At this point, the lever arm engagesthe contact 66 to energize the solenoid 38 to pull the holder to the left together with the ball transfer plate 2|, to'the starting position.

By cutting the recesses or grooves 22 away at the right hand side, it lets the ball slide out of the groove into the ball transfer to release the same. In this way, the balls are lowered into the grinding position held by the holders or pins I4 in their concave upper ends. In this position, the lever 55 is set to slide onto the contact 59 when the balls are in the position between the holders or pins l4 or in the position intermediate that shown in Figure 1 of the drawings. At this time, the coil 24 is energized by the closing of the circuit therethrough, so as to again pick up the balls be'ingground and allow a newone to be picked up from the receptacle or cup 50. When the holder is to the right, actuated by the spring 39, the solenoid 4| is energized to raise the slide or plunger 44 and permit another balllto enter the opening 45, and upon de-energization of magnet 4| spring 53 lowers plunger 44 to opening 48 bringing it in line with the tube 49 and letting one ball'enter or roll into the cup 50. When the holder slides back to the left pulled by the solenoid 38 against the action of the spring 39 upon energization of the coil-or solenoid 38, the electro-magnetic member or solenoid 4| is deenergized and the spring 53 pulls the slide downwardly to release the ball. On the other hand, when the ball transfer and holder are at the starting position, the mechanism operated by the lever 65 and contact 66, being tripped by the lever to operate the bar lifting device of the usual grinding machine, is turned off, which allows the springs 31 to raise the bar 26 or holder formed thereby upwardly, taking the balls out of the grinding position and raising them high enough to clear the ribs of the wheels and cups or holders formed by the pins l4, so that they can be moved to line up with the next group of wheels and pins I4.

It will thus be seen that I have provided a magnetic ball transfer, which is very simple in construction and operation, and eliminates much of the complicated mechanism of the devices heretofore in use, while entirely automatically and magnetically operated. This is true as to the release as well as the raising and lowering of the balls during the grinding operation until the latter is accurately completed.

While in the foregoing there has 'been shown and described the preferred embodiment of this invention it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

What I claim is:

l. A magnetic ball transfer including a frame having uprights, a ball holder slidable horizontally therein and normally held in one position and movable to another position, means to move the holder to different positions, electro-magnetic means for holding the same in the other position, means electrically operated for automatically feeding ball singly to receiving position, an electro-magnet carried by said holder, means for raising and lowering said electro-magnet, means for receiving the balls in the different positions, said magnet having recesses cut out at one side to release the balls when shifted, means controlling said actuating means, and receiving means for the balls.

2. In a ball transfer and feeding device for a centerless grinder for grinding ball bearings or the like, a frame, a holder reciprocable horizontally of the frame, a magnetic plate movable vertically in the holder and normally held in an elevated position, said plate having a plurality of spaced ball receiving recesses, at its lower end a ball holder mounted beneath the recesses, a plunger movable vertically and normally held in a lowered position, said plunger having a ball receiving opening, mean for feeding balls singularly to said opening when the plunger is elevated, a ball receiving cup mounted beneath the first ball receiving recess, a. passage leading from the opening when in a lowered position to convey the balls to the cup singly, magnetic means intermittently operated to elevate the plunger for receivingua ball and .to discharge'same upon de of electrical energy to advance the balls into suc-.

cessive grinding-positions in the holders below the recesses and to discharge the balls from the end recess at the end opposite the cup after operations thereon by. the grinding wheels of the grindin'g'machine, and means for receiving and discharging the ground balls.

3; A magnetic ball transfer for grindingmachines having opposed series of grinding wheels adapted for grinding action upon the balls therebetween .in grinding positions, including a frame, a holder movable in the frame, magnetic means carried by said holder, means for intermittently raising and lowering the magnetic means, ball receiving means, means for singly feeding the balls to the receiving means, means for holding the balls in grinding positions, said magnetic means adapted to engage and bodily raise the balls from the receiving means and the holding means after being ground by the wheels and to move the same progressively along the holding means and series of grinding wheels to different grinding positions therebetween and to release the same to the next holders upon being lowered and de-magnetized, and means for automatically actuating said feeding means, raising and lowering means for the.

magnetic means and moving the latter to receiving and releasing positions and for magnetizing and de-magnetizing said magnetic means in sequence.

4. A magnetic ball transfer for grinding machines having opposed rows of grinding wheels defining grinding positions therebetween, including a frame having uprights, ball holding means between the wheels, means for intermittently feeding the balls singly to the holding means, means movable in the uprights for bodilylifting the balls from the holding means and intermittently moving the sameprogressively across the holding means, means for lowering said lifting and moving means at each end of its movement, means for releasing the balls therefrom when moved, and means for discharging the balls upon completion of the grinding action thereon after passing the last grinding wheels and being raised from the holding means therebetween.

5. The combination with a grinding machine having opposed rows of grinding wheels defining grinding positions therebetween, a magnetic ball transfer including a frame having uprights, a holder movable in said uprights, means for firmly holding the holder to one side, ball receiving seats between the rows of grinding wheels for receiving the balls in grinding position, means to singly feed the balls to the seats, magnetic means to move the holder to the other side against the balls across the rows of grinding wheels..itol:successive grinding 'positions,"means to lower'ithe holder for depositing the balls upon the i'seats progressively across the rows, for action thereon by the grinding wheels, dischargemeansfor the balls upon lowering of the holder means and deenergization thereof, and :means automatically controlling said feeding, raising and release means.

.6. The combination with a. grinding .'machine having a series of opposed rows of grinding wheels defining grinding. positions therebetweemia magnetic ball transfer including a frameIhaving-uprights, a holder movable therein, means firmly holding the holder to one side, magnetic means to move the holder'to the other side against the action of the first named means, magnetic means for energizing said holder, means for raising: and lowering said magneticholder means, means for automatically feeding the balls singly, a receiving member for receiving said balls, means for progressively raising and moving the balls progressively across the various grinding'wheelsto grinding positions therebetween and for progressively advancing the same across the grinding positions, seats for holdingthe balls in said grinding positions, means for discharging the balls upon the lowering thereof with the holder means and de-energization thereof, and means for automatically controlling said feeding, raising and release means. I

7. In a ball transfer and feeding device for a grinder for grinding ball bearings or the like, a frame, a holder reciprocable horizontally of the frame, a magnetic plate movable vertically in the holder, saidplate having a plurality of spaced ball receiving recesses at its lower end, ball holders mounted beneath the recesses, means for feeding balls singly, a ball receiving cup mounted beneath the first ball receiving recess, means to intermittently lower the magnetic plate to engage and lift a ball from the cup, means to move theholder and plate in a direction opposed to the feedingdirection for engagement with the ball, means to move the holder and plate in thefeeding direction across the grinding wheels to successive grinding positions, seats between the respective opposed grinding wheels in the grinding positions to hold the balls while being ground, said balls being fed step by step from the cup to successive recesses and grinding positions-and means to discharge the iballsffroml the send recess atithe end opposite the cup after operation thereon by the grinding wheels of the grinding machine. 8. 'A magnetic :ball transfer for grinding machines having opposed :grinding'wheels defining a grinding position therebetween, including means forzh'olding the balls in grinding. position, a receptacle'for receiving balls to be ground, means for'feeding the balls. singly to'the receptacle, means for magnetically raisingl the balls from the receptacle and from grinding position, means for moving said magnetic means to Iadvancethe position of the balls from the receptacleto the holding means in grinding position and from the holding means in grinding position to a'discharge position beyond the holdingmeans,and means for releasing the balls from. thermag'netic means when moved to an advancedposition above the holding means and to a discharge position. l

9. A magnetic ball transfer for grindingmachines having opposed series of grinding wheels between which the balls are adapted'to be held in grinding positions,- including means for holding the. balls in grinding positions, a receptacle for receiving the balls to be ground, means for feeding the balls singly tolthe receptacle, means for magnetically'raising theb'alls bodily fromthe receptacle and from the. grinding: positions, means for moving said magnetic means to advance the position of the ballsjfrom the'receptacle to the holding means and simultaneously from the holding means to successive holding means and beyond the latter for discharge intermittently in the raised positions, means for releasing the balls when advanced, and means for returning said raising means to its initial position.

JOHN A. SW'ENTON.

REFERENCES CITED The following referencesare of recordin the file of this patent: V UNITED STATES PATENTS Number 7 Name Date 1,141,412 Pool Junel, 1915 1,877,515 Liljeberg Sept. 13, 1932 1,893,213 Vuilleumier Jan. 3, 1933 2,143,026 Nordquist Jan. 10, 1939 

